Have you tried deleting old Windows 8 files?
I had the same problem which went away after I cleaned up my hard disk.
Hi,
I have the same problem. Since I've updated my Dell XPS 8300 to Windows 8.1 I have to wait for three minutes to see the login screen. Two additional minutes elapse before the start-screen come in view.
Meanwhile using Windows 8 everything was fine.
I've changed the most important drivers and ran CClear. I am lost.